Planta

, Volume 199, Issue 1, pp 43–49

Hydrogen peroxide-mediated cell-wall stiffening in vitro in maize coleoptiles

  • P. Schopfer
Article

DOI: 10.1007/BF00196879

Cite this article as:
Schopfer, P. Planta (1996) 199: 43. doi:10.1007/BF00196879

Abstract

It has recently been proposed that H2O2-dependent peroxidative formation of phenolic cross-links between cell-wall polymers serves as a mechanism for fixing the viscoelastically extended wall structure and thus confers irreversibility to wall extension during cell growth (M. Hohl et al. 1995, Physiol. Plant. 94: 491–498). In the present paper the isolated cell wall (operationally, frozen/thawed maize coleoptile segments) was used as an experimental system to investigate H2O2-dependent cell-wall stiffening in vitro. Hydrogen peroxide inhibited elongation growth (in vivo) and decreased cell-wall extensibility (in vitro) in the concentration range of 10–10000 μmol·1−1. In rheological measurements with a constant-load extensiometer the stiffening effect of H2O2 could be observed with both relaxed and stressed cell walls. In-vitro cell-wall stiffening was a time-dependent reaction that lasted about 60 min in the presence of saturating concentrations of H2O2. The presence of peroxidase in the growth-limiting outer epidermal wall of the coleoptile was shown by histochemical assays. Peroxidase inhibitors (azide, ascorbate) suppressed the wall-stiffening reaction by H2O2 in vitro. Hydrogen peroxide induced the accumulation of a fluorescent, insoluble material in the cell walls of living coleoptile segments. These results demonstrate that primary cell walls of a growing plant organ contain all ingredients for the mechanical fortification of the wall structure by H2O2-inducible phenolic cross-linking.

Key words

Cell-wall stiffening (coleoptile)Coleoptile growthHydrogen peroxidePeroxidaseZea coleoptile (cell-wall stiffening)

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • P. Schopfer
    • 1
  1. 1.Institut für Biologie II der UniversitätFreiburgGermany